Species

islets of langerhans

Summary

Summary: Irregular microscopic structures consisting of cords of endocrine cells that are scattered throughout the PANCREAS among the exocrine acini. Each islet is surrounded by connective tissue fibers and penetrated by a network of capillaries. There are four major cell types. The most abundant beta cells (50-80%) secrete INSULIN. Alpha cells (5-20%) secrete GLUCAGON. PP cells (10-35%) secrete PANCREATIC POLYPEPTIDE. Delta cells (~5%) secrete SOMATOSTATIN.

Janakiraman KrishnamurthyDepartment of Medicine, The Lineberger Comprehensive Cancer Center, The University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USANature 443:453-7. 2006

In the mammalian pancreas, the endocrine cell types of the islets of Langerhans, including the alpha-, beta-, delta-, and pancreatic polypeptide cells as well as the exocrine cells, derive from foregut endodermal progenitors...

..These findings implicate an inflammatory process in the pathogenesis of glucotoxicity in type 2 diabetes and identify the IL-1beta/NF-kappaB pathway as a target to preserve beta cell mass and function in this condition...

Dual roles for glucokinase in glucose homeostasis as determined by liver and pancreatic beta cell-specific gene knock-outs using Cre recombinase

..Interestingly, hepatic GK knock-out mice also have impaired insulin secretion in response to glucose. These studies indicate that deficiencies in both beta cell and hepatic GK contribute to the hyperglycemia of MODY-2...

Janakiraman KrishnamurthyDepartment of Medicine, The Lineberger Comprehensive Cancer Center, The University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USANature 443:453-7. 2006

..These genetic data support the view that an age-induced increase of p16INK4a expression limits the regenerative capacity of beta-cells with ageing...

..For type 1 diabetes, as remission develops, progression from stage 4 to stage 2 is typically found. Delineation of these stages provides insight into the pathophysiology of both progression and remission of diabetes...

Autophagy is important in islet homeostasis and compensatory increase of beta cell mass in response to high-fat diet

..have used RNA sequencing (RNA-seq) to identify transcripts, including splice variants, expressed in human islets of Langerhans under control conditions or following exposure to the pro-inflammatory cytokines interleukin-1β (IL-1β) ..

..A default pathway would explain the elevated number of alpha cells in the absence of Pax4...

Prolonged exposure to free fatty acids has cytostatic and pro-apoptotic effects on human pancreatic islets: evidence that beta-cell death is caspase mediated, partially dependent on ceramide pathway, and Bcl-2 regulated

Roberto LupiDepartment of Endocrinology and Metabolism, University of Pisa, Pisa, ItalyDiabetes 51:1437-42. 2002

..The cytostatic action is likely to be due to the FFA-induced reduction of intraislet glucose metabolism, and the proapoptotic effects are mostly caspase mediated, partially dependent on ceramide pathway, and possibly Bcl-2 regulated...

Reduced beta-cell mass and expression of oxidative stress-related DNA damage in the islet of Japanese Type II diabetic patients

..The latter process requires an increase in cytosolic Ca2+, which depends on ATP synthesized by the mitochondria. This organelle also generates other factors, of which glutamate has been proposed as a potential intracellular messenger...

..We propose that chronic hyperglycemia, independent of hyperlipidemia, is toxic for beta-cell function, whereas chronic hyperlipidemia is deleterious only in the context of concomitant hyperglycemia...

The estrogenic effect of bisphenol A disrupts pancreatic beta-cell function in vivo and induces insulin resistance

..C57BL/6J mice exhibit impaired glucose tolerance. The aims of this study were to map the genetic loci underlying this phenotype, to further characterise the physiological defects and to identify candidate genes...

How punctual ablation of regulatory T cells unleashes an autoimmune lesion within the pancreatic islets

..e. coinciding with the peak of beta-cell proliferation. In summary, our results suggest the existence of an endothelial-endocrine axis within adult pancreatic islets, which is of importance for adult beta-cell proliferation...

Cellular and molecular events in the localization of diabetogenic T cells to islets of Langerhans

..Collectively, these data portray the kinetics of CTL homing to and between antigenic target sites as a stochastic process at the sub-organ level and argue against a dominant influence of chemotactic gradients...

Maternal diet and aging alter the epigenetic control of a promoter-enhancer interaction at the Hnf4a gene in rat pancreatic islets

..A detailed characterization of these "gene modules", and of the signalling pathways and transcription factors regulating them could allow us to understand the ultimate mechanisms leading to beta-cell apoptosis...

..The results demonstrate that FFA(1)R/GPR40 is inhibited by the CPT-1 inhibitor, 2BrP, and confirm that FFA(1)R/GPR40 is indeed necessary, at least in part, for fatty-acid-stimulated insulin release...

..This identification of a differentiated pancreatic cell type as an in vivo progenitor of all differentiated pancreatic cell types has implications for a potential expandable source for new islets for replenishment therapy for diabetes...

..We conclude that NO depletes ER Ca(2+), causes ER stress, and leads to apoptosis. Thus, ER Ca(2+) stores are a new target of NO, and the ER stress pathway is a major mechanism of NO-mediated beta cell apoptosis...

..2 and Pax4 are required to specify or maintain differentiation of the beta cell fate. This finding also suggests that there is a genetic component underlying the balance between insulin and ghrelin in regulating glucose metabolism...

..4 +/- 0.2% (n = 6) of the cells in the pancreas of newborn (P1) and 0.9 +/- 0.1% (n = 5) of 8-wk-old mice were beta-cells. The MIP-GFP-transgenic mouse may be a useful tool for studying beta-cell biology in normal and diabetic animals...

..Here, we examined DNA methylation of the insulin gene promoter in pancreatic islets from patients with type 2 diabetes and non-diabetic human donors and related it to insulin expression, HbA(1c) levels, BMI and age...

..Agonists that can change the rate-limiting steps for both phases of insulin release include those like glucagon-like peptide 1 (GLP-1) that raise cyclic AMP levels and those like acetylcholine that act via DAG...

Unraveling the role of the ghrelin gene peptides in the endocrine pancreas

..The present review summarizes the newest findings on AG, UAG, and Ob expression in pancreatic islets and the role of these peptides on beta-cell development, survival, and function...

Response of human islets to isolation stress and the effect of antioxidant treatment

Rita BottinoDepartment of Pediatrics, University of Pittsburgh, School of Medicine, Pennsylvania, USADiabetes 53:2559-68. 2004

The process of human islet isolation triggers a cascade of stressful events in the islets of Langerhans involving activation of apoptosis and necrosis and the production of proinflammatory molecules that negatively influence islet yield ..

Adaptation of islets of Langerhans to pregnancy: beta-cell growth, enhanced insulin secretion and the role of lactogenic hormones

cAMP is a critical messenger for insulin and glucagon secretion from pancreatic β- and α-cells, respectively. Dispersed β-cells show cAMP oscillations, but the signaling kinetics in cells within intact islets of Langerhans is unknown.

..Besides the available drugs that act on K(ATP) channels and increase the triggering signal, novel drugs that correct a deficient amplifying pathway would be useful to restore adequate insulin secretion in type 2 diabetic patients...

DESCRIPTION (provided by applicant): Deposition of islet amyloid pancreatic polypeptide (IAPP) in the islets of Langerhans is the characteristic feature of human type 2 diabetic pancreas but represents the final stage of a process ..

..mediated by CD4 T cells that leads to the destruction of the insulin producing beta cells in the pancreatic islets of Langerhans. Once the beta cells are destroyed, blood sugar levels are unable to be controlled due to the lack of ..

..in part, from its ability to stimulate the secretion of insulin from pancreatic beta cells located in the islets of Langerhans. Given the established importance of GLP-1 for the treatment of diabetes, our laboratory is interested in ..

DESCRIPTION (provided by applicant): There is a fundamental gap in understanding how the islets of Langerhans function in vivo, either in the native environment in the pancreas or after transplantation to treat type 1 diabetes...

DESCRIPTION (provided by applicant): The endocrine pancreas, composed of the islets of Langerhans, is responsible for the maintenance of blood glucose homeostasis. Several cell types comprise the islets and include glucagon-producing ...

..is characterized by the autoimmune-mediated destruction of the insulin producing [unreadable] cells of the islets of Langerhans. Our work and that of others in murine models has shown that transferring genes for immunoregulatory ..

..it develops pancreatic islet cell carcinomas in a multi-step pathway arising from normal beta cells in the islets of Langerhans through two distinct premalignant stages to highly vascularized large adenomas and invasive carcinomas...

..an autoimmune disease characterized by the destruction of the insulin producing beta cells residing in the islets of Langerhans. In order to provide a "cure" for chronic diabetic individuals the beta cell mass that has been destroyed ..

..disease that is characterized by selective destruction of insulin secreting beta-cells found in pancreatic islets of Langerhans. Viral infection is one event proposed to initiate beta-cell damage during the development of this disease...

A hallmark of Type 2 diabetes is impaired insulin secretion from beta cells of the islets of Langerhans. Greater understanding of islets and insulin secretion is of fundamental importance in determining the root causes of diabetes and ..

DESCRIPTION (provided by applicant): The islets of Langerhans which are distributed throughout the pancreas comprise 1-2% of the mass of the pancreas and contain the endocrine cells that secrete insulin (beta-cells) and other hormones...

..successfully completed SBIR Phase I and Phase II research demonstrating that magnetically labeled porcine islets of Langerhans can be isolated from contaminating exocrine tissue by flow sorting using a quadrupole magnetic separator ("..

Type I diabetes (T1D) is a spontaneous autoimmune disease in which the insulin-producing beta cells of the islets of langerhans are destroyed as a consequence of inflammatory reactions triggered by genetic and environmental factors...

..role of phospholipases and heterotrimeric GTP-binding proteins in insulin secretion by the beta-cells of islets of Langerhans. The metabolism of glucose is sufficient for insulin secretion by islets of Langerhans...

..to be learned about the etiology and pathogenesis of diabetes, transplantation of the whole pancreas or islets of Langerhans represents potential means of curing the conditions that are worthy of serious investigation...

..Finally, the characterization and identification of a phosphoprotein intermediate localized to the endoplasmic reticulum Ca2+-ATPase will be performed to correlate further the Ca2+-ATPase with Ca2+ transport by this organelle...

..Such control might be possible with pancreatic transplant or transplantation of isolated islets of Langerhans. Isolated islets of Langerhans, transplanted in an immune privileged site such as the testis, or with ..

..mechanisms, possible etiologic agent(s) and the natural history of the interplay of autoimmunity and the islets of Langerhans, as it relates to the pathogenesis of insulin dependent diabetes (IDDM)...

..of this project is to develop a novel in vitro technique for measurement of total cell volume in samples of islets of Langerhans that will be useful for assessing the quality of islet preparations for pancreatic transplantation and ..

..is essential for both efficient adhesion and for transendothelial migration of T killer cells into the islets of Langerhans. After penetration into the islets, cytotoxic T cells cause the destruction of insulin-producing p cells...

Insulin-dependent diabetes mellitus (IDDM) is characterized by the infiltration of T-lymphocytes into the islets of Langerhans of the pancreas (insulitis), followed by selective destruction of insulin-secreting beta-cells leading to overt ..

Type 1 insulin-dependent diabetes mellitus is caused by an autoimmune attack on the islets of Langerhans. The susceptibility to this disease is determined both genetically and by environmental events...

DESCRIPTION (taken from the application) Insulin production in the islets of Langerhans is regulated by Multiple hormonal, neuronal and paracrine factors acting through interconnected signal transduction pathways...

The past decade has seen a burgeoning of interest in the biology of the pancreatic islets of Langerhans. The surge in activity is driven in large measure by the rapid increase in the incidence of diabetes, and the critical role of failure ..

..to determine how glucose and other nutrients regulate gene expression in the beta-cells of the pancreatic islets of langerhans and to apply this knowledge to understanding the pathophysiology of NIDDM...

..the molecular mechanisms underlying the formation of the insulin-producing Beta-cells in the pancreatic islets of Langerhans and to apply this knowledge to the replacement of the absent or defective Beta-cells in patients with ..